SENATE ADVANCES BORDER SECURITY PLAN: The Senate on Monday moved toward adopting significant changes to the border security provisions in its comprehensive immigration bill, a move seen as crucial to attracting a broad majority of support for the landmark legislation, FUSION's JORDAN FABIAN reports. Sixty-seven senators, including 15 Republicans, voted to limit debate on a Republican amendment aimed at quelling worries over future border security. The measure would initiate a massive buildup of Border Patrol agents and the completion of 700 miles of fencing along the U.S.-Mexico border before legalized immigrants can obtain permanent residence. The vote on the proposal, which was co-written by Sens. Bob Corker (R-Tenn.) and John Hoeven (R-N.D.), clears the way for a final vote on the overall bill later this week. The amendment is likely the last major change to underlying bill that will be considered ahead of the vote before the full Senate, which is expected Thursday. http://abcn.ws/1aapT6S

BAY STATE BATTLE: After a brief but hard-fought campaign, it all comes to an end today in Massachusetts where voters will decide who will replace Secretary of State John Kerry in the United States Senate. ABC's SHUSHANNAH WALSHE notes that polls show Rep. Ed Markey, D-Mass., ahead by at least 10 points, but businessman and former Navy SEAL Gabriel Gomez was still pushing forward in the last days, even holding ten events yesterday. Although it's still likely Markey will win, it could depend on turnout. If Gomez can make it close and there is lackluster attendance at the polls, GOP outside groups that never ended up throwing money Gomez's way may come to regret their decision and Team Gomez could be saying, "I told you so."

FLIGHT RISK? Wherever he is, NSA leaker Edward Snowden has triggered a diplomatic war of words between the United States and Russia reminiscent of the Cold War, ABC's BRIAN ROSS reports. For a second day in a row, Snowden was a no-show on flight from Russia to Havana, Cuba this morning. "He doesn't have a Russian visa, and that means he can't leave the airport," ABC's KIRIT RADIA reports. "That means the only way he can get out is on a flight." Meanwhile, Russia's foreign minister Sergey Lavrov responded angrily to U.S. allegations that Russia was hiding Snowden, saying that such claims were "absolutely ungrounded and unacceptable," but he refused to say where Snowden is. At the White House yesterday, Press Secretary Jay Carney turned up the pressure, saying, "We expect the Russians to examine the options available to them to expel Mr. Snowden for his return to the United States." WATCH ABC's "Good Morning America" team coverage for the latest on the hunt for Snowden:http://abcn.ws/146YE8v

THE ROUNDTABLE

ABC's JEFF ZELENY: Immigration reform is on the cusp of passing the Senate. With 67 senators voting Monday evening to move forward with the debate, the bill is heading toward its final step in the Senate before the week's end. It has something of an anti-climactic feel to it. But that will change when the Second Act of this legislative fight begins. House Republicans now see themselves as a critical line of defense in stopping the bill. Senate supporters believe a 70-vote margin will force the hand of the House. One GOP congressman laughed at that suggestion yesterday when I asked him about it. The question is whether the Chamber of Commerce and other conservative business groups advocating reform will have any influence on the debate when it reaches the lower chamber. Right now, there are few signs that they will.

ABC's RICK KLEIN: Barring a genuine shocker - remember that Scott Brown was leading in polls going into his special election - a Democrat will continue to represent Massachusetts in John Kerry's old Senate seat. After today's election, look for some mild Republican second-guessing about what might have been, if Gabriel Gomez comes inside, say, single digits of Rep. Ed Markey. The bigger takeaway, though, could come on the other side: A clear Markey win would be an important psychological victory for Democrats. Democrats shouldn't have to worry about Senate seats in Massachusetts any more than Republicans do in Mississippi. Markey may or may not have needed all the national help. But Democrats look like they did what needed to be done - and welcome the return to normalcy signaled by the continuing all-Democratic congressional representation in the Bay State.

HAPPENING TODAY: This afternoon, President Obama outlines his plan to tackle climate change. In a 1:55 p.m. Eastern speech at Georgetown University, the president will call for new standards to reduce carbon pollution from both new and existing power plants, among other steps, ABC's MARY BRUCE notes. Later, the president and vice president meet with members of the Congressional Leadership in the Oval Office, including Senate Majority Leader Harry Reid, Senate Republican Leader Mitch McConnell, Speaker John Boehner, and House Democratic Leader Nancy Pelosi.

WHAT WE'RE WATCHING

ECONOMICS 101: MEET THE STUDENTS WHO WILL PAY IF CONGRESS MISSES STUDENT LOAN DEADLINE. Brandon Anderson, a 28-year-old Iraq war veteran, is in pursuit of the American dream. After spending five years in the military and two more at a community college, Anderson was able to transfer to Georgetown University to complete his education. What has made it all possible, Anderson told ABC's JEFF ZELENY, host of "The Fine Print," is government-subsidized student loans. "I could not attend college here or probably anywhere else without the student loan program," Anderson says, estimating that he'll graduate $25,000 in debt. But the interest rates on the Stafford loans upon which Anderson and about 7 million other financially needy students across the country rely are set to double on July 1 from the current 3.4 percent interest rate to 6.8 percent - unless Congress acts to prevent it. The House and Senate are at odds over how to address student loan rates. http://yhoo.it/18dhvmy

BUZZ

EXCLUSIVE: BUSH INSTITUTE BACKS IMMIGRATION REFORM. A new book published today by the George W. Bush Institute says there is no viable economic reason to keep the 11 million undocumented immigrants in the shadows and promotes the need for immigration reform, ABC's JIM AVILA and SERENA MARSHALL report. The book, co-sponsored by the U.S. Hispanic Chamber of Commerce, finds immigration reform is good for job creation and adds to the economy through growth. "Its stagnant," Matthew Denhard, research fellow at the George W. Bush Institute and book author said of the U.S. labor force in an exclusive interview with ABC News. "The native-born workforce is becoming older." Whereas, he says, 70 percent of immigrants are of working age between 25 and 64. "When we talk about small businesses - 18 percent of all small business owners in the U.S. are immigrants," he said. "Whereas only about 13 percent of all people in the U.S. are immigrants … immigrants fill gaps in our labor force. And we were talking about high skilled and low skilled immigrants." Denhard's research, which is encapsulated in the new book, "Growth and Immigration: A Handbook of Vital Immigration and Economic growth Statistics," found immigrant-owned businesses generate an estimated $775 billion in annual revenue. http://abcn.ws/19ykPq6

NOTED: OBAMA HIGHLIGHTS IMMIGRANT SUCCESS STORIES. On the theory nothing succeeds like success, President Obama listened to the success stories of immigrants who came to the U.S. and founded major corporate enterprises, urging them to carry their support for immigration reform to the Senate as it completes work on landmark legislation, ABC's ANN COMPTON notes. "I would urge the Senate to bring this to the floor," he told the visiting entrepreneurs. "I hope that we can get the strongest possible vote out of the Senate so that we can then move to the House and get this done before the summer break." Alex Torrenegra described how he could not get a visa to work in the U.S. when he came at the age of 18 from Colombia. He told President Obama he enrolled as a student but started small businesses on the side. He founded VoiceBunny, described as the largest database of voice actors on the planet for voices used in video games, movies and electronic devices. http://abcn.ws/131eD9R

IRS SAYS IT SCREENED GROUPS BASED ON 'QUESTIONABLE CRITERIA' UNTIL JUNE. Not only did the Internal Revenue Service continue using inappropriate criteria to screen organizations applying for tax-exempt status until mid-June, it now appears that in addition to conservative groups, liberal groups were also targeted for higher scrutiny, IRS Principal Deputy Commissioner Danny Werfel said yesterday, according to ABC's ABBY PHILLIP. Werfel also acknowledged that until he discovered the use of such criteria during an internal review of the agency, other "be on the lookout" or BOLO lists were in place that screened applications for 501(c)4 tax exempt status based on a wide range of "questionable criteria" including the word "progressive." Though the public outrage over the IRS targeting initially focused on conservative groups, new documents released late on Monday show that groups identified as "progressive" were also singled out on BOLO lists by the IRS from 2010 until at least July 2012. And a slew of other groups, including green energy organizations, medical marijuana groups, and "paying national debt" groups were also singled out. The documents, which were made available to the House Ways and Means Committee appear to bolster the IRS's long-standing assertion that the practice of singling out groups was not politically motivated, but rather it stemmed from an effort to identify groups that may have been engaged in more political activity than is allowed under the tax code. http://abcn.ws/16vo6Vr

IN SUPREME COURT BRIEF, KEN CUCCINELLI WARNED OF A SLIPPERY SLOPE FROM GAY MARRIAGE TO POLYGAMY. Virginia gubernatorial candidate Ken Cuccinelli's opposition to gay marriage is well established. But as the U.S. Supreme Court prepares to issue decisions on two major gay marriage cases this week, less well-known is his co-authorship, in January 2013, of a court brief that laid out an argument against the constitutionality of allowing same-sex couples to marry, ABC's MICHAEL FALCONE reports. In the amicus brief, Cuccinelli, the attorney general of Virginia, and Greg Zoeller, the attorney general or Indiana, used a novel justification to make their point in one section of the 55-page brief - namely that gay marriage could lead to polygamy. "Responsible parenting is not a justification for same-sex-couple marriage, as distinguished from recognition of any other human relationships. It is instead a rationale for eliminating marriage as government recognition of a limited set of relationships. Once the natural limits that inhere in the relationship between a man and a woman can no longer sustain the definition of marriage, the conclusion that follows is that any grouping of adults would have an equal claim to marriage. See, e.g. , Jonathan Turley, One Big, Happy Polygamous Family , NY Times, July 21, 2011, at A27 ("[Polygamists] want to be allowed to create a loving family according to the values of their faith.")." (The article that Cuccinelli and Zoeller cite is a July 2011 Op-Ed in The New York Times authored by Jonathan Turley, a law professor at The George Washington University Law School, which argues that polygamy should be decriminalized.) It was just one of several citations the two attorneys general used in their brief submitted to the U.S. Supreme Court in the landmark case, Hollingsworth v. Perry, which arrived at the high court after a panel of judges in the Ninth Circuit determined that California's Proposition 8, the controversial ballot initiative that banned gay marriage in the state, was unconstitutional. http://abcn.ws/17aAJWW

FROM THE CUCCINELLI CAMPAIGN: "Virginians voted overwhelmingly to change their constitution to define marriage as only between one man and one woman. The Supreme Court's decision in the California case could have implications for all states with such marriage amendments," the Cuccinelli campaign's press secretary Anna Nix said in a statement. "As it's the attorney general's duty to vigorously protect Virginia's laws when they are challenged, he filed a brief with several other states in this case and used every available legal argument to defend the law and the will of the people of the commonwealth."

NEW AIR FORCE LEADER BECOMES HIGHEST-RANKING OPENLY-GAY PERSON AT PENTAGON. Undersecretary of the Air Force for just two months, Eric Fanning is now the acting civilian leader of the military branch after the retirement Friday of Air Force Secretary Michael Donley made him the highest-ranking openly-gay person at the Defense Department, ABC's GARRETT BRUNO notes. Fanning, having started his career in the Pentagon in the '90s, will fill the role until President Obama nominates an official replacement. "'Don't Ask, Don't Tell' was implemented when I got [to the Pentagon]," Fanning said in an interview with the Washington Blade. "I didn't know what I was going to do if we didn't get the repeal through because some people couldn't work because they were openly gay or lesbian." Although never subjected to the "Don't Ask, Don't Tell" policy as a civilian leader, Fanning said the changes that have occurred regarding gays in the military so far have been encouraging, especially since his return to the Pentagon in 2009. http://abcn.ws/176ZoLK

IN THE NOTE'S INBOX

BLOOMBERG GROUP MAPS OUT BENEFITS OF IMMIGRATION. The Partnership for a New American Economy, New York Mayor Michael Bloomberg's pro-immigration reform group, released a new interactive 50-state map showing the economic benefits of immigration. According to the map, "In California, immigrants founded more than one third of the state's businesses; in Delaware, 64 percent of the engineering PhD graduates are foreign born; in Colorado, immigrant-owned businesses generate more than $1 billion per year for the state; in New York, foreign born seasonal workers supported 16,611 jobs that could not have existed otherwise." http://maptheimpact.org